1. Technical Field
The present invention relates to a pneumatic grinder with improved muffling structure, and more particularly, to a pneumatic grinder exhausting waste air with reduced noise.
2. Description of Related Art
Implementing high-pressure airflow to drive a pneumatic motor and in turn propel a grinding wheel to rotate is the operational principle upon which a pneumatic grinder is based. Therefore, it is necessary for such a pneumatic grinder to discharge waste air which has passed through the pneumatic motor to the outside for promoting air circulation. According to conventional design, a pneumatic grinder typically has the waste air guided to and discharged through an exhaust port provided at the rear part or either side thereof. One problem with such a design is that noise can be considerably generated during air exhaust. Though silencing cotton has been added to a conventional pneumatic grinder, as shown in FIG. 4, for the purpose of reducing noise, it is still not an effective solution to moderate the piercing noise brought by the discharge of waste air. Such noise can consequently induce hearing loss of a perpetual pneumatic grinder operator.